Analog-to-digital converters (ADCs) are commonly used to convert analog signals, such as voltage or current signals, into digital codes that can be processed by a computer system. For example, an ADC may receive a voltage signal that varies over time and convert the voltage signal into a stream of digitally encoded values in binary format. The ADC may divide the dynamic range of the received voltage signal into a number of levels, where each level is represented by a different binary code.
ADCs can be used in sensor applications, where an electrical signal generated by a sensor (such as a transducer) is converted to a digital code. For instance, the sensor output may provide an analog voltage or current to an input of an ADC. In some cases, the accuracy of the sensor may be degraded if the ADC to which it is connected draws too much current. An ADC with a low input impedance, for example, may draw too much current from the sensor output, dropping the sensor's output voltage.